Sarda, Nandlal L (1990) Extensions to SQL for Historical Databases. In: IEEE Transactions on Knowledge and Data Engineering, 2 (2). pp. 220-230.
A historical database management system (HDBMS) is a high-level facility which provides timing information and automatically maintains history (i.e., past) data. It also provides facilities for time-related queries. One such HDBMS is described in this paper. Our HDBMS uses an extended relational data model with state-oriented, instead of cubic, conceptualization. Two types of historical relations, called state and event relations, are provided for modeling realworld objects. The popular query langauge SQL has been extended for definition, retrieval, and update of historical relations. The extended SQL, called HSQL, is a superset of SQL. We define a few primitive algebra operations for historical relations, and use them as a basis for extensions to SQL. By doing so, HSQL retains the elegant structural and algebraic framework of SQL. HSQL contains a few new clauses, many operations and built-in functions on time domain, and facilities for retrospective updates and time-rollback.
|Item Type:||Journal Article|
|Additional Information:||Copyright 1990 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.|
|Keywords:||Data models;Database management;Historical database; Modeling of time;Query languages;Relational algebra;Relational model;SQL|
|Department/Centre:||Division of Electrical Sciences > Computer Science & Automation (Formerly, School of Automation)|
|Date Deposited:||25 Aug 2008|
|Last Modified:||19 Sep 2010 04:27|
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